DR. KATHLEEN WALKER MAYER MD
NPI 1457488439
Internal Medicine in Bakersfield, CA
About Dr. Kathleen Walker Mayer Md NPPES
Official registry information on file with the National Plan and Provider Enumeration System.
DR. KATHLEEN WALKER MAYER MD (NPI 1457488439) is an individual internal medicine provider in Bakersfield, California, licensed in California (C176095) and active in the NPI registry since February 2007. She is enrolled in Medicare PECOS and is a graduate of Other (1997).
NPPES Registry Identity
Specialties & Licenses
Medicare Participation & PECOS CMS
Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.
Medicare Enrollment Status
Enrolled in Medicare (PECOS)
Dr. Kathleen Walker Mayer Md is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).
Medicare Billing Reassignments
5Medicare enrollment records show Kathleen Mayer reassigns Medicare billing to 5 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.
Bakersfield, CA 93309
- Reassigned Medicare billing, California enrollment
- Medicare enrollment name: Form Health Associates PC
- 13 clinicians in this Medicare group
Denver, CO 80205
- Reassigned Medicare billing, California, Minnesota and Ohio enrollments
- Medicare enrollment name: Cirrusmd Medical Group Of Delaware PA
- 8 clinicians in this Medicare group
Spokane, WA 99201
- Reassigned Medicare billing, North Carolina and Tennessee enrollments
- 6 clinicians in this Medicare group
Dallas, TX 75219
- Reassigned Medicare billing, Texas enrollment
- 55 clinicians in this Medicare group
Boston, MA 02109
- Reassigned Medicare billing, Illinois enrollment
- 23 clinicians in this Medicare group
Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.
Physician Visit Costs CMS claims · ZIP area
Typical Medicare office-visit costs in the 93309 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.
Referred Medical Equipment & Supplies CMS DME claims 2
Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.
Other Providers at the Same Location NPPES 5
Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.
BAKERSFIELD, CA 93309
BAKERSFIELD, CA 93309
BAKERSFIELD, CA 93309
Frequently Asked Questions NPPES & CMS
Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.
What is Kathleen Mayer's NPI number?
The NPI number for Kathleen Mayer is 1457488439. It was assigned to this individual provider in the NPPES registry on February 27, 2007.
Where is Kathleen Mayer located?
Kathleen Mayer practices at 4900 California Ave Fl 2, Bakersfield, CA 93309. The listed phone number is (617) 505-1520.
What is Kathleen Mayer's specialty?
The primary specialty registered for this NPI is Internal Medicine with taxonomy code 207R00000X.
Is Kathleen Mayer enrolled in Medicare?
Yes. Kathleen Mayer is registered in the Medicare PECOS enrollment system.
Which organizations bill Medicare for Kathleen Mayer's services?
According to the CMS Revalidation Reassignment List (October 2026 release), Kathleen Mayer reassigns Medicare benefits to 5 organizations: Form Health Associates, P.C. (Bakersfield, CA), Cirrusmd Medical Group Of Delaware, P.A. (Denver, CO), Cmdpn Medical Group Of Washington P C (Spokane, WA), Cmdpn Medical Group Of Texas, P.A. (Dallas, TX) and Form Health Associates Ma, P.C. (Boston, MA). Each reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Kathleen Mayer's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.
When was this NPI record last updated?
The NPPES record for Kathleen Mayer was last updated on June 11, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 4 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.
# Dr. Kathleen Walker Mayer, MD · NPI 1457488439
Internal Medicine physician in Bakersfield, California. Individual provider, active in the CMS NPPES registry since February 27, 2007.
## Identity
- **NPI:** 1457488439 (Entity type: Individual)
- **Enumerated:** February 27, 2007
- **Primary specialty:** Internal Medicine · taxonomy 207R00000X
- **State license:** C176095 (California)
- **Sole proprietor:** No
## Practice location
- **Address:** 4900 CALIFORNIA AVE FL 2, Bakersfield, CA 93309-7024
- **Phone:** (617) 505-1520 · **Fax:** (617) 928-8401
## Medicare
- **Medicare:** Enrolled in Medicare (PECOS)
- **Ordering & referring:** eligible for Part B labs & imaging, durable medical equipment, home health, power mobility devices
- **Bills Medicare through:** 5 organizations under Medicare reassignment (form CMS-855R): Form Health Associates, P.C. (NPI 1043835044, Bakersfield, CA); Cirrusmd Medical Group Of Delaware, P.A. (NPI 1922664200, Denver, CO); Cmdpn Medical Group Of Washington P C (NPI 1316422454, Spokane, WA); Cmdpn Medical Group Of Texas, P.A. (NPI 1174082150, Dallas, TX); Form Health Associates Ma, P.C. (NPI 1386260594, Boston, MA) · CMS Revalidation Reassignment List, October 2026 release
- **Medical school:** Other, class of 1997
## Record status
- **NPPES last updated:** June 11, 2026
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Source: [NPI Profile](https://npiprofile.com/npi/1457488439) · Data from the CMS NPPES public registry.